Underground air-raid shelter feeding London restaurants

LONDON - Under an anonymous back street in south London lies a vast underground air-raid shelter that has been turned into a pioneering urban farm supplying supermarkets and restaurants in the capital.

The World War II shelter in Clapham, which could protect up to 8,000 people from Nazi German bombs, consists of two large tunnels that were intended to one day become an extension of the London Underground.

That never happened and the shelter lay abandoned for 70 years until two entrepreneurs, Steven Dring and Richard Ballard, decided to grow broccoli, coriander, fennel and a host of other vegetables as so-called micro leaves, also known as micro herbs, grown from seedlings but harvested early when the first leaves form.

"We need to create these new fertile spaces" to meet increased demand from a growing global population, Dring said at the "Growing Underground" site - some 33 meters below the road.

Staff wear protective clothing and there is a strong smell of vegetables and humidity in the shelter.

The vegetables are grown with hydroponics, using nutrient solutions in a water solvent instead of soil.

The technique can also be used to grow a wide range of produce including tomatoes and baby peppers, Dring said.

The tunnels have no natural light and are illuminated with pink LEDs, giving them a futuristic look.

The intensity changes to imitate daylight, but with one major difference - the lights are dimmed during the day and shine brightest at night, as electricity is cheapest then.

"We predominantly grow micro herbs, which are standard herbs, from different seeds. But what we do is we grow them to a very small stage, before the first true leaves start to come out," Dring said.

The micro herb broccoli takes between three and five days to grow before being packaged up and sent off.

Experts say vertical and urban farming could be ways not only of facing up to population growth but also growing urbanization worldwide as well as climate change.

Every day is the same in the underground farm and there are no seasons, or unpredictable British weather.

"We have a lot more control than usual growers. ... When in the winter days it's cold under the glass, it will take you 25 days to grow red mustard. It will always take us 10 days to grow red mustard," Dring said.

He added: "There's nothing that stands as a major challenge, apart from building a farm underneath London."

Agence France-presse